A narrow roadway clings to the mountain side as the road rises at a steep slope from sea level to the pass high above. Rivers of earth that begin up on the mountain flow down under the roadway and carry dirt and rock that spill into the deep ravine on the other side. Eventually they begin to carry the road with them and disrupt traffic on this steep and dangerous but vital link from below to above.
Though flows may be dug out and hauled away, piers are also built on either side of them and the roadway spans the rivers of earth like a bridge over water. The piers are anchored and supported by pylons driven down into bedrock. The pylons also create a density of earth and rocks between them that impedes the rate of flow, but never completely. Otherwise, the pressure would build to such an extent that the pylons would fail.
Members of the faithful religious community, Christians, Jews, and Muslims, are the pylons that anchor the roadway. They also limit as much as possible the rate and extent of cross flow that threatens to wash out the vital pathway to cultural stability, civility, spirituality and refinement.